IP Multimedia Subsystem (IMS) is a framework for adding multimedia services to mobile communication networks to support delivery of Internet Protocol (IP) services and aid the access of multimedia and voice applications from wireless and wireline networks to create a convergence between fixed networks and mobile networks. IP Multimedia Subsystem provides a control layer that isolates the access network from the service layer. This control layer allows network operators to provide multimedia services in a scalable, centralized manner.
Long Term Evolution (LTE) is a standard for wireless communication of high-speed data for mobile phones and data terminals. Long Term Evolution is an evolution of the Global System for Mobile Communications (GSM) and Universal Mobile Telecommunications System (UMTS). Long Term Evolution was designed to increase the capacity and speed of wireless data networks using new digital signaling processing (DSP) and modulation techniques and a simplification of the network architecture to an Internet Protocol-based system. The Long Term Evolution wireless interface is incompatible with the previous standards and must be operated on a separate wireless spectrum.